Item14335: utf8 encode before calculating signatures

The HMAC routines can't deal with wide characters

SMELL:  This is Foswiki 2.x ONLY.  It needs to be conditional for
backwards compatibiltiy with Foswiki 1.x.  However several of the other
changes are also 2.x only, so this extension needs work to be backwards
compatibile:

lib/Foswiki/Plugins/SafeWikiPlugin/Signatures.pm

@@ -207,16 +207,17 @@ s/<!--safewiki:([0-9A-Za-z\/\+]{27}):([^;]+);;(.*?)-->/$unhoist->($1,$2,$3)/eg;
     %TMP_SIGNATURES = ();
 }
 
+#SMELL: Foswiki::encode_utf8 is Foswiki 2.x only!
 sub getMAC {
     my $text = shift;
     my $key  = $Foswiki::cfg{Plugins}{SafeWikiPlugin}{SecretKey};
-    my $mac  = Digest::HMAC_SHA1->new($key);
-    $mac->add($text);
+    my $mac  = Digest::HMAC_SHA1->new( Foswiki::encode_utf8($key) );
+    $mac->add( Foswiki::encode_utf8($text) );
     return $mac->b64digest;
 }
 
 # Simple: hash a piece of code
-sub getSHA { return sha256_base64(shift); }
+sub getSHA { return sha256_base64( Foswiki::encode_utf8(shift) ); }
 
 # Check if we have the signature for a piece of code in our whitelist
 sub checkSHA { return _haveSHA( getSHA(shift) ); }